There is an imperfection in get_vmx_mem_address(): access length is ignored
when checking the limit. To fix this, pass access length as a function argument.
The access length is usually obvious since it is used by callers after
get_vmx_mem_address() call, but for vmread/vmwrite it depends on the
state of 64-bit mode.
Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Intel SDM vol. 3, 5.3:
The processor causes a
general-protection exception (or, if the segment is SS, a stack-fault
exception) any time an attempt is made to access the following addresses
in a segment:
- A byte at an offset greater than the effective limit
- A word at an offset greater than the (effective-limit – 1)
- A doubleword at an offset greater than the (effective-limit – 3)
- A quadword at an offset greater than the (effective-limit – 7)
Therefore, the generic limit checking error condition must be
exn = (off > limit + 1 - access_len) = (off + access_len - 1 > limit)
but not
exn = (off + access_len > limit)
as for now.
Also avoid integer overflow of `off` at 32-bit KVM by casting it to u64.
Note: access length is currently sizeof(u64) which is incorrect. This
will be fixed in the subsequent patch.
Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add support to expose Intel V2 Extended Topology Enumeration Leaf for
some new systems with multiple software-visible die within each package.
Because unimplemented and unexposed leaves should be explicitly reported
as zero, there is no need to limit cpuid.0.eax to the maximum value of
feature configuration but limit it to the highest leaf implemented in
the current code. A single clamping seems sufficient and cheaper.
Co-developed-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make all code consistent with kvm_deliver_exception_payload() by using
appropriate symbolic constant instead of hard-coded number.
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Even when asynchronous page fault is disabled, KVM does not want to pause
the host if a guest triggers a page fault; instead it will put it into
an artificial HLT state that allows running other host processes while
allowing interrupt delivery into the guest.
However, the way this feature is triggered is a bit confusing.
First, it is not used for page faults while a nested guest is
running: but this is not an issue since the artificial halt
is completely invisible to the guest, either L1 or L2. Second,
it is used even if kvm_halt_in_guest() returns true; in this case,
the guest probably should not pay the additional latency cost of the
artificial halt, and thus we should handle the page fault in a
completely synchronous way.
By introducing a new function kvm_can_deliver_async_pf, this patch
commonizes the code that chooses whether to deliver an async page fault
(kvm_arch_async_page_not_present) and the code that chooses whether a
page fault should be handled synchronously (kvm_can_do_async_pf).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It doesn't seem as if there is any particular need for kvm_lock to be a
spinlock, so convert the lock to a mutex so that sleepable functions (in
particular cond_resched()) can be called while holding it.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
__vmcs_writel uses volatile asm, so there is no need to insert another
one between the first and the second call to __vmcs_writel in order
to prevent unwanted code moves for 32bit targets.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
While upstream gcc doesn't detect conflicts on cc (yet), it really
should, and hence "cc" should not be specified for asm()-s also having
"=@cc<cond>" outputs. (It is quite pointless anyway to specify a "cc"
clobber in x86 inline assembly, since the compiler assumes it to be
always clobbered, and has no means [yet] to suppress this behavior.)
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Fixes: bbc0b82392 ("KVM: nVMX: Capture VM-Fail via CC_{SET,OUT} in nested early checks")
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is the same as vm_vcpu_add_default, but it also takes a
kvm_vcpu_init struct pointer.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This allows aarch64 tests to run on more targets, such as the Arm
simulator that doesn't like KVM_ARM_TARGET_GENERIC_V8. And it also
allows aarch64 tests to provide vcpu features in struct kvm_vcpu_init.
Additionally it drops the unused memslot parameters.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make sure we complete the I/O after determining we have a ucall,
which is I/O. Also allow the *uc parameter to optionally be NULL.
It's quite possible that a test case will only care about the
return value, like for example when looping on a check for
UCALL_DONE.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
MSR IA32_MISC_ENABLE bit 18, according to SDM:
| When this bit is set to 0, the MONITOR feature flag is not set (CPUID.01H:ECX[bit 3] = 0).
| This indicates that MONITOR/MWAIT are not supported.
|
| Software attempts to execute MONITOR/MWAIT will cause #UD when this bit is 0.
|
| When this bit is set to 1 (default), MONITOR/MWAIT are supported (CPUID.01H:ECX[bit 3] = 1).
The CPUID.01H:ECX[bit 3] ought to mirror the value of the MSR bit,
CPUID.01H:ECX[bit 3] is a better guard than kvm_mwait_in_guest().
kvm_mwait_in_guest() affects the behavior of MONITOR/MWAIT, not its
guest visibility.
This patch implements toggling of the CPUID bit based on guest writes
to the MSR.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Fixes for backwards compatibility - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allow guest reads CORE cstate when exposing host CPU power management capabilities
to the guest. PKG cstate is restricted to avoid a guest to get the whole package
information in multi-tenant scenario.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit b31c114b (KVM: X86: Provide a capability to disable PAUSE intercepts)
forgot to add the KVM_X86_DISABLE_EXITS_PAUSE into api doc. This patch adds
it.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1. Using X86_FEATURE_ARCH_CAPABILITIES to enumerate the existence of
MSR_IA32_ARCH_CAPABILITIES to avoid using rdmsrl_safe().
2. Since kvm_get_arch_capabilities() is only used in this file, making
it static.
Signed-off-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a wrapper to invoke kvm_arch_check_processor_compat() so that the
boilerplate ugliness of checking virtualization support on all CPUs is
hidden from the arch specific code. x86's implementation in particular
is quite heinous, as it unnecessarily propagates the out-param pattern
into kvm_x86_ops.
While the x86 specific issue could be resolved solely by changing
kvm_x86_ops, make the change for all architectures as returning a value
directly is prettier and technically more robust, e.g. s390 doesn't set
the out param, which could lead to subtle breakage in the (highly
unlikely) scenario where the out-param was not pre-initialized by the
caller.
Opportunistically annotate svm_check_processor_compat() with __init.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
AVIC doorbell is used to notify a running vCPU that interrupts
has been injected into the vCPU AVIC backing page. Current logic
checks only if a VCPU is running before sending a doorbell.
However, the doorbell is not necessary if the destination
CPU is itself.
Add logic to check currently running CPU before sending doorbell.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Advance lapic timer tries to hidden the hypervisor overhead between the
host emulated timer fires and the guest awares the timer is fired. However,
it just hidden the time between apic_timer_fn/handle_preemption_timer ->
wait_lapic_expire, instead of the real position of vmentry which is
mentioned in the orignial commit d0659d946b ("KVM: x86: add option to
advance tscdeadline hrtimer expiration"). There is 700+ cpu cycles between
the end of wait_lapic_expire and before world switch on my haswell desktop.
This patch tries to narrow the last gap(wait_lapic_expire -> world switch),
it takes the real overhead time between apic_timer_fn/handle_preemption_timer
and before world switch into consideration when adaptively tuning timer
advancement. The patch can reduce 40% latency (~1600+ cycles to ~1000+ cycles
on a haswell desktop) for kvm-unit-tests/tscdeadline_latency when testing
busy waits.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
wait_lapic_expire() call was moved above guest_enter_irqoff() because of
its tracepoint, which violated the RCU extended quiescent state invoked
by guest_enter_irqoff()[1][2]. This patch simply moves the tracepoint
below guest_exit_irqoff() in vcpu_enter_guest(). Snapshot the delta before
VM-Enter, but trace it after VM-Exit. This can help us to move
wait_lapic_expire() just before vmentry in the later patch.
[1] Commit 8b89fe1f6c ("kvm: x86: move tracepoints outside extended quiescent state")
[2] https://patchwork.kernel.org/patch/7821111/
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Track whether wait_lapic_expire was called, and do not invoke the tracepoint
if not. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Extract adaptive tune timer advancement logic to a single function.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Rename new function. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit 8c5fbf1a72 ("KVM/nSVM: Use the new mapping API for mapping guest
memory") broke nested SVM completely: kvm_vcpu_map()'s second parameter is
GFN so vmcb_gpa needs to be converted with gpa_to_gfn(), not the other way
around.
Fixes: 8c5fbf1a72 ("KVM/nSVM: Use the new mapping API for mapping guest memory")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Intel MKTME repurposes several high bits of physical address as 'keyID'
for memory encryption thus effectively reduces platform's maximum
physical address bits. Exactly how many bits are reduced is configured
by BIOS. To honor such HW behavior, the repurposed bits are reduced from
cpuinfo_x86->x86_phys_bits when MKTME is detected in CPU detection.
Similarly, AMD SME/SEV also reduces physical address bits for memory
encryption, and cpuinfo->x86_phys_bits is reduced too when SME/SEV is
detected, so for both MKTME and SME/SEV, boot_cpu_data.x86_phys_bits
doesn't hold physical address bits reported by CPUID anymore.
Currently KVM treats bits from boot_cpu_data.x86_phys_bits to 51 as
reserved bits, but it's not true anymore for MKTME, since MKTME treats
those reduced bits as 'keyID', but not reserved bits. Therefore
boot_cpu_data.x86_phys_bits cannot be used to calculate reserved bits
anymore, although we can still use it for AMD SME/SEV since SME/SEV
treats the reduced bits differently -- they are treated as reserved
bits, the same as other reserved bits in page table entity [1].
Fix by introducing a new 'shadow_phys_bits' variable in KVM x86 MMU code
to store the effective physical bits w/o reserved bits -- for MKTME,
it equals to physical address reported by CPUID, and for SME/SEV, it is
boot_cpu_data.x86_phys_bits.
Note that for the physical address bits reported to guest should remain
unchanged -- KVM should report physical address reported by CPUID to
guest, but not boot_cpu_data.x86_phys_bits. Because for Intel MKTME,
there's no harm if guest sets up 'keyID' bits in guest page table (since
MKTME only works at physical address level), and KVM doesn't even expose
MKTME to guest. Arguably, for AMD SME/SEV, guest is aware of SEV thus it
should adjust boot_cpu_data.x86_phys_bits when it detects SEV, therefore
KVM should still reports physcial address reported by CPUID to guest.
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As a prerequisite to fix several SPTE reserved bits related calculation
errors caused by MKTME, which requires kvm_set_mmio_spte_mask() to use
local static variable defined in mmu.c.
Also move call site of kvm_set_mmio_spte_mask() from kvm_arch_init() to
kvm_mmu_module_init() so that kvm_set_mmio_spte_mask() can be static.
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Several bug fixes for the new XIVE-native code.
- Replace kvm->lock by other mutexes in several places where we hold a
vcpu mutex, to avoid lock order inversions.
- Fix a lockdep warning on guest entry for radix-mode guests.
- Fix a bug causing user-visible corruption of SPRG3 on the host.
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Merge tag 'kvm-ppc-fixes-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master
PPC KVM fixes for 5.2
- Several bug fixes for the new XIVE-native code.
- Replace kvm->lock by other mutexes in several places where we hold a
vcpu mutex, to avoid lock order inversions.
- Fix a lockdep warning on guest entry for radix-mode guests.
- Fix a bug causing user-visible corruption of SPRG3 on the host.
The sprgs are a set of 4 general purpose sprs provided for software use.
SPRG3 is special in that it can also be read from userspace. Thus it is
used on linux to store the cpu and numa id of the process to speed up
syscall access to this information.
This register is overwritten with the guest value on kvm guest entry,
and so needs to be restored on exit again. Thus restore the value on
the guest exit path in kvmhv_p9_guest_entry().
Cc: stable@vger.kernel.org # v4.20+
Fixes: 95a6432ce9 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Under XIVE, the ESB pages of an interrupt are used for interrupt
management (EOI) and triggering. They are made available to guests
through a mapping of the XIVE KVM device.
When a device is passed-through, the passthru_irq helpers,
kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped(), clear the ESB
pages of the guest IRQ number being mapped and let the VM fault
handler repopulate with the correct page.
The ESB pages are mapped at offset 4 (KVM_XIVE_ESB_PAGE_OFFSET) in the
KVM device mapping. Unfortunately, this offset was not taken into
account when clearing the pages. This lead to issues with the
passthrough devices for which the interrupts were not functional under
some guest configuration (tg3 and single CPU) or in any configuration
(e1000e adapter).
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
According to Documentation/virtual/kvm/locking.txt, the srcu read lock
should be taken when accessing the memslots of the VM. The XIVE KVM
device needs to do so when configuring the page of the OS event queue
of vCPU for a given priority and when marking the same page dirty
before migration.
This avoids warnings such as :
[ 208.224882] =============================
[ 208.224884] WARNING: suspicious RCU usage
[ 208.224889] 5.2.0-rc2-xive+ #47 Not tainted
[ 208.224890] -----------------------------
[ 208.224894] ../include/linux/kvm_host.h:633 suspicious rcu_dereference_check() usage!
[ 208.224896]
other info that might help us debug this:
[ 208.224898]
rcu_scheduler_active = 2, debug_locks = 1
[ 208.224901] no locks held by qemu-system-ppc/3923.
[ 208.224902]
stack backtrace:
[ 208.224907] CPU: 64 PID: 3923 Comm: qemu-system-ppc Kdump: loaded Not tainted 5.2.0-rc2-xive+ #47
[ 208.224909] Call Trace:
[ 208.224918] [c000200cdd98fa30] [c000000000be1934] dump_stack+0xe8/0x164 (unreliable)
[ 208.224924] [c000200cdd98fa80] [c0000000001aec80] lockdep_rcu_suspicious+0x110/0x180
[ 208.224935] [c000200cdd98fb00] [c0080000075933a0] gfn_to_memslot+0x1c8/0x200 [kvm]
[ 208.224943] [c000200cdd98fb40] [c008000007599600] gfn_to_pfn+0x28/0x60 [kvm]
[ 208.224951] [c000200cdd98fb70] [c008000007599658] gfn_to_page+0x20/0x40 [kvm]
[ 208.224959] [c000200cdd98fb90] [c0080000075b495c] kvmppc_xive_native_set_attr+0x8b4/0x1480 [kvm]
[ 208.224967] [c000200cdd98fca0] [c00800000759261c] kvm_device_ioctl_attr+0x64/0xb0 [kvm]
[ 208.224974] [c000200cdd98fcf0] [c008000007592730] kvm_device_ioctl+0xc8/0x110 [kvm]
[ 208.224979] [c000200cdd98fd10] [c000000000433a24] do_vfs_ioctl+0xd4/0xcd0
[ 208.224981] [c000200cdd98fdb0] [c000000000434724] ksys_ioctl+0x104/0x120
[ 208.224984] [c000200cdd98fe00] [c000000000434768] sys_ioctl+0x28/0x80
[ 208.224988] [c000200cdd98fe20] [c00000000000b888] system_call+0x5c/0x70
legoater@boss01:~$
Fixes: 13ce3297c5 ("KVM: PPC: Book3S HV: XIVE: Add controls for the EQ configuration")
Fixes: e6714bd167 ("KVM: PPC: Book3S HV: XIVE: Add a control to dirty the XIVE EQ pages")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The XICS-on-XIVE KVM device needs to allocate XIVE event queues when a
priority is used by the OS. This is referred as EQ provisioning and it
is done under the hood when :
1. a CPU is hot-plugged in the VM
2. the "set-xive" is called at VM startup
3. sources are restored at VM restore
The kvm->lock mutex is used to protect the different XIVE structures
being modified but in some contexts, kvm->lock is taken under the
vcpu->mutex which is not permitted by the KVM locking rules.
Introduce a new mutex 'lock' for the KVM devices for them to
synchronize accesses to the XIVE device structures.
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
When a vCPU is connected to the KVM device, it is done using its vCPU
identifier in the guest. Fix the enforced limit on the vCPU identifier
by taking into account the SMT mode.
Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
When a CPU is hot-unplugged, the EQ is deconfigured using a zero size
and a zero address. In this case, there is no need to check the flag
and queue size validity. Move the checks after the queue reset code
section to fix CPU hot-unplug.
Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Improve the release of the XIVE KVM device by clearing the file
address_space, which is used to unmap the interrupt ESB pages when a
device is passed-through.
Suggested-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently the HV KVM code takes the kvm->lock around calls to
kvm_for_each_vcpu() and kvm_get_vcpu_by_id() (which can call
kvm_for_each_vcpu() internally). However, that leads to a lock
order inversion problem, because these are called in contexts where
the vcpu mutex is held, but the vcpu mutexes nest within kvm->lock
according to Documentation/virtual/kvm/locking.txt. Hence there
is a possibility of deadlock.
To fix this, we simply don't take the kvm->lock mutex around these
calls. This is safe because the implementations of kvm_for_each_vcpu()
and kvm_get_vcpu_by_id() have been designed to be able to be called
locklessly.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently the Book 3S KVM code uses kvm->lock to synchronize access
to the kvm->arch.rtas_tokens list. Because this list is scanned
inside kvmppc_rtas_hcall(), which is called with the vcpu mutex held,
taking kvm->lock cause a lock inversion problem, which could lead to
a deadlock.
To fix this, we add a new mutex, kvm->arch.rtas_token_lock, which nests
inside the vcpu mutexes, and use that instead of kvm->lock when
accessing the rtas token list.
This removes the lockdep_assert_held() in kvmppc_rtas_tokens_free().
At this point we don't hold the new mutex, but that is OK because
kvmppc_rtas_tokens_free() is only called when the whole VM is being
destroyed, and at that point nothing can be looking up a token in
the list.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently the HV KVM code uses kvm->lock in conjunction with a flag,
kvm->arch.mmu_ready, to synchronize MMU setup and hold off vcpu
execution until the MMU-related data structures are ready. However,
this means that kvm->lock is being taken inside vcpu->mutex, which
is contrary to Documentation/virtual/kvm/locking.txt and results in
lockdep warnings.
To fix this, we add a new mutex, kvm->arch.mmu_setup_lock, which nests
inside the vcpu mutexes, and is taken in the places where kvm->lock
was taken that are related to MMU setup.
Additionally we take the new mutex in the vcpu creation code at the
point where we are creating a new vcore, in order to provide mutual
exclusion with kvmppc_update_lpcr() and ensure that an update to
kvm->arch.lpcr doesn't get missed, which could otherwise lead to a
stale vcore->lpcr value.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently, kvmppc_xive_release() and kvmppc_xive_native_release() clear
kvm->arch.mmu_ready and call kick_all_cpus_sync() as a way of ensuring
that no vcpus are executing in the guest. However, future patches will
change the mutex associated with kvm->arch.mmu_ready to a new mutex that
nests inside the vcpu mutexes, making it difficult to continue to use
this method.
In fact, taking the vcpu mutex for a vcpu excludes execution of that
vcpu, and we already take the vcpu mutex around the call to
kvmppc_xive_[native_]cleanup_vcpu(). Once the cleanup function is
done and we release the vcpu mutex, the vcpu can execute once again,
but because we have cleared vcpu->arch.xive_vcpu, vcpu->arch.irq_type,
vcpu->arch.xive_esc_vaddr and vcpu->arch.xive_esc_raddr, that vcpu will
not be going into XIVE code any more. Thus, once we have cleaned up
all of the vcpus, we are safe to clean up the rest of the XIVE state,
and we don't need to use kvm->arch.mmu_ready to hold off vcpu execution.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
KVM_CAP_MAX_VCPU_ID is currently always reporting KVM_MAX_VCPU_ID on all
architectures. However, on s390x, the amount of usable CPUs is determined
during runtime - it is depending on the features of the machine the code
is running on. Since we are using the vcpu_id as an index into the SCA
structures that are defined by the hardware (see e.g. the sca_add_vcpu()
function), it is not only the amount of CPUs that is limited by the hard-
ware, but also the range of IDs that we can use.
Thus KVM_CAP_MAX_VCPU_ID must be determined during runtime on s390x, too.
So the handling of KVM_CAP_MAX_VCPU_ID has to be moved from the common
code into the architecture specific code, and on s390x we have to return
the same value here as for KVM_CAP_MAX_VCPUS.
This problem has been discovered with the kvm_create_max_vcpus selftest.
With this change applied, the selftest now passes on s390x, too.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20190523164309.13345-9-thuth@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We also need to fence the memunmap part.
Fixes: e45adf665a ("KVM: Introduce a new guest mapping API")
Fixes: d30b214d1d (kvm: fix compilation on s390)
Cc: Michal Kubecek <mkubecek@suse.cz>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
GCC 9 now warns about calling memset() on partial structures when it
goes across multiple fields. This adds a helper for the place in
tracing that does this type of clearing of a structure.
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Merge tag 'trace-v5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing warning fix from Steven Rostedt:
"Make the GCC 9 warning for sub struct memset go away.
GCC 9 now warns about calling memset() on partial structures when it
goes across multiple fields. This adds a helper for the place in
tracing that does this type of clearing of a structure"
* tag 'trace-v5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Silence GCC 9 array bounds warning
merge window, but should not wait four months before they appear in
a release. I also travelled a bit more than usual in the first part
of May, which didn't help with picking up patches and reports promptly.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"The usual smattering of fixes and tunings that came in too late for
the merge window, but should not wait four months before they appear
in a release.
I also travelled a bit more than usual in the first part of May, which
didn't help with picking up patches and reports promptly"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (33 commits)
KVM: x86: fix return value for reserved EFER
tools/kvm_stat: fix fields filter for child events
KVM: selftests: Wrap vcpu_nested_state_get/set functions with x86 guard
kvm: selftests: aarch64: compile with warnings on
kvm: selftests: aarch64: fix default vm mode
kvm: selftests: aarch64: dirty_log_test: fix unaligned memslot size
KVM: s390: fix memory slot handling for KVM_SET_USER_MEMORY_REGION
KVM: x86/pmu: do not mask the value that is written to fixed PMUs
KVM: x86/pmu: mask the result of rdpmc according to the width of the counters
x86/kvm/pmu: Set AMD's virt PMU version to 1
KVM: x86: do not spam dmesg with VMCS/VMCB dumps
kvm: Check irqchip mode before assign irqfd
kvm: svm/avic: fix off-by-one in checking host APIC ID
KVM: selftests: do not blindly clobber registers in guest asm
KVM: selftests: Remove duplicated TEST_ASSERT in hyperv_cpuid.c
KVM: LAPIC: Expose per-vCPU timer_advance_ns to userspace
KVM: LAPIC: Fix lapic_timer_advance_ns parameter overflow
kvm: vmx: Fix -Wmissing-prototypes warnings
KVM: nVMX: Fix using __this_cpu_read() in preemptible context
kvm: fix compilation on s390
...
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Merge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull /dev/random fix from Ted Ts'o:
"Fix a soft lockup regression when reading from /dev/random in early
boot"
* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
random: fix soft lockup when trying to read from an uninitialized blocking pool
Fixes: eb9d1bf079bb: "random: only read from /dev/random after its pool has received 128 bits"
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Starting with GCC 9, -Warray-bounds detects cases when memset is called
starting on a member of a struct but the size to be cleared ends up
writing over further members.
Such a call happens in the trace code to clear, at once, all members
after and including `seq` on struct trace_iterator:
In function 'memset',
inlined from 'ftrace_dump' at kernel/trace/trace.c:8914:3:
./include/linux/string.h:344:9: warning: '__builtin_memset' offset
[8505, 8560] from the object at 'iter' is out of the bounds of
referenced subobject 'seq' with type 'struct trace_seq' at offset
4368 [-Warray-bounds]
344 | return __builtin_memset(p, c, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
In order to avoid GCC complaining about it, we compute the address
ourselves by adding the offsetof distance instead of referring
directly to the member.
Since there are two places doing this clear (trace.c and trace_kdb.c),
take the chance to move the workaround into a single place in
the internal header.
Link: http://lkml.kernel.org/r/20190523124535.GA12931@gmail.com
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
[ Removed unnecessary parenthesis around "iter" ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Bug fixes (including a regression fix) for ext4"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix dcache lookup of !casefolded directories
ext4: do not delete unlinked inode from orphan list on failed truncate
ext4: wait for outstanding dio during truncate in nojournal mode
ext4: don't perform block validity checks on the journal inode
Eugene Korenevsky
Like Xu
Liran Alon
Paolo Bonzini
Junaid Shahid
Uros Bizjak
Gustavo A. R. Silva
Jan Beulich
Andrew Jones
Wanpeng Li
Xiaoyao Li
Sean Christopherson
Suthikulpanit, Suravee
Vitaly Kuznetsov
Kai Huang
Suraj Jitindar Singh
Paul Mackerras
Cédric Le Goater
Thomas Huth
Christian Borntraeger
Linus Torvalds
Theodore Ts'o
Miguel Ojeda